This invention relates generally to alternating current power sources and more particularly, but not by way of limitation, to a reserve alternating current power supply for a computer.
To power electrical devices there is the need for some source of power. Quite frequently, the power is to be of the alternating current (AC) type rather than the direct current (DC) type. Although the electrical device might ultimately require DC power, such DC power can be obtained from an AC power source, such as by a rectification process as known to the art. Therefore, there is the general need for an alternating current power source.
By way of a specific example, an electronic computer needs to be energized by some type of power source. Although components of the computer might ultimately require DC power, AC power is frequently used as the primary source from which the DC power can be derived. Therefore, in energizing an electronic computer, the commercial AC power supply obtained from a wall socket or the like is frequently used. However, because the commercial AC power supply is susceptible to power interruptions, such as outages or brown-outs, there is the further need for a second alternating current power source which can function as a back-up to the commercial supply or, alternatively, as the primary supply if so desired. That this need has arisen is indicated in U.S. Pat. No. 4,038,559 to Chun et al. which discloses a system having two alternating current power sources and which also discloses other prior art techniques.
Regardless of the specific use of such an alternating current power source, there is the need that such a power source properly control its power output by monitoring the power output.
When functioning in a reserve mode, such a power source should automatically detect power interruptions and apply its power to prevent damage to or improper operation of the electrical load being powered.
Such a power source functioning in a reserve mode should also automatically monitor and reconnect the primary power source to the load when the primary power source returns to proper operation. Disconnection of the reserve power source should also be performed by the power source once the primary source has been reconnected.
To insure that the reserve power source will be available when a primary power interruption occurs, the reserve power source should have the capability of being recharged by the primary power source when the primary power source is operating properly.
Indications perceptible to an operator should also be provided by such a power source so that the present operating status can be quickly determined.